BACKGROUND: Cellular and functional changes secondary to aging could impair myocardial tolerance to ischemia and affect the heart's response to ischemic preconditioning. METHODS: We investigated the impact of cardiac aging on preconditioning in right atrial trabeculae of adult patients (< or = 55 years) and senescent patients (> or = 70 years) with coronary artery disease. Specimens were subjected to 30 minutes of simulated ischemia (hypoxic substrate-free superfusion) with and without 5 minutes of ischemic pretreatment. Postischemic contractile recovery was measured and expressed as percentage of base line force values. RESULTS: During the reoxygenation period, trabeculae of adult patients but not those of senescent patients improved after ischemic preconditioning. After 40 minutes of reoxygenation, preconditioned adult trabeculae developed 57% +/- 5% of their preischemic force (nonpreconditioned control 44% +/- 5%, p < 0.01), senescent trabeculae recovered to 44% +/- 4% (control 45% +/- 3%). Especially myocardium from adult patients with Canadian Cardiovascular Society (CCS) stage III angina pectoris treated with ACE inhibitors recovered well (70% +/- 7%; control 50% +/- 8%, p < 0.01), contrasting with trabeculae from patients with CCS stage II angina (44% +/- 5%; control 40% +/- 10%). Ischemia-inducible Hsp70 (human heat shock protein) was additionally measured after reoxygenation. Total Hsp70 mRNA was elevated in preconditioned myocardium along with its contractile recovery (r = 0.33, p = 0.07). Because the control transcription, analyzing 18S rRNA and beta-actin, was reduced by ischemia but recovered in preconditioned trabeculae, relative Hsp70 mRNA was not altered. CONCLUSIONS: Our data indicate that ischemic preconditioning has no beneficial effect on the postischemic functional recovery of senescent human myocardium.
BACKGROUND: Cellular and functional changes secondary to aging could impair myocardial tolerance to ischemia and affect the heart's response to ischemic preconditioning. METHODS: We investigated the impact of cardiac aging on preconditioning in right atrial trabeculae of adult patients (< or = 55 years) and senescent patients (> or = 70 years) with coronary artery disease. Specimens were subjected to 30 minutes of simulated ischemia (hypoxic substrate-free superfusion) with and without 5 minutes of ischemic pretreatment. Postischemic contractile recovery was measured and expressed as percentage of base line force values. RESULTS: During the reoxygenation period, trabeculae of adult patients but not those of senescent patients improved after ischemic preconditioning. After 40 minutes of reoxygenation, preconditioned adult trabeculae developed 57% +/- 5% of their preischemic force (nonpreconditioned control 44% +/- 5%, p < 0.01), senescent trabeculae recovered to 44% +/- 4% (control 45% +/- 3%). Especially myocardium from adult patients with Canadian Cardiovascular Society (CCS) stage III angina pectoris treated with ACE inhibitors recovered well (70% +/- 7%; control 50% +/- 8%, p < 0.01), contrasting with trabeculae from patients with CCS stage II angina (44% +/- 5%; control 40% +/- 10%). Ischemia-inducible Hsp70 (human heat shock protein) was additionally measured after reoxygenation. Total Hsp70 mRNA was elevated in preconditioned myocardium along with its contractile recovery (r = 0.33, p = 0.07). Because the control transcription, analyzing 18S rRNA and beta-actin, was reduced by ischemia but recovered in preconditioned trabeculae, relative Hsp70 mRNA was not altered. CONCLUSIONS: Our data indicate that ischemic preconditioning has no beneficial effect on the postischemic functional recovery of senescent human myocardium.
Authors: Yasushi Mio; Martin W Bienengraeber; Jasna Marinovic; David D Gutterman; Mladen Rakic; Zeljko J Bosnjak; Anna Stadnicka Journal: Anesthesiology Date: 2008-04 Impact factor: 7.892
Authors: F Mármol; J Sánchez; D López; N Martínez; J Roselló-Catafau; M T Mitjavila; P Puig-Parellada Journal: J Physiol Biochem Date: 2007-09 Impact factor: 4.158